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XL On the Development of Electricity between Metals and Heated 

 Salts. By W. G. Haxkel*. 



ALTHOUGH it occurred to Scliwcigger^ soon after the dis- 

 covery of his multipher, to bring salts iu the fused state, 

 instead of their aqueous solutions, between two dissimilar metals 

 in the voltaic circuit, j^et Andrews in Belfast was the tirst (in 

 1837) to apply Faraday's discovery of the high conductive power 

 of certain salts in the melted state to the solution of the question 

 whether electricity is developed when two metals of the same 

 chemical nature, but of dissimilar temperatures, are brought into 

 contact with the same fused salt, in a manner similar to that in 

 which the thermo-electrical currents of Seebeck are formed. 

 Andrews found that, under the circumstances described, a cur- 

 rent was formed, proceeding from the hotter to the colder metal, 

 passing through the melted mass of the salt. He was, however, 

 unable to determine the law for the direction of the stream when 

 the salt was only heated so far as to enable it to conduct the 

 electricity, but not sufficiently to bring it into a state of fusion. 



The interest attached to these electrical phaeuomena appeared 

 to me to render a re-examination of the matter necessary. The 

 following paper, which I have the honour to lay before the 

 Konigliche Gesellschaft dcr Wissenschaften as the third in the 

 scries of my electrical in\ estigatious, contains the results of my 

 experiments with numerous salts concerning the development of 

 electrical currents under the conditions described. 



The paper is divided into two parts, tlie first of v.hich contains 

 the general results derived from the facts observed ; the second 

 contains these facts in a condensed form, and thus serves in a 

 manner as an appendix to the first part. 



1 shall in the first place describe, for the sake of perspicuity, 

 the process which I have made use of in my investigations, and 

 then consider shortly the general results which have been derived 

 from them. 



The salt under examination was brought into a moderately 

 sized platinum crucible supported on platinum wire, and fused 

 by means of a spirit-lamp with double draught, the draught 

 being, when necessary, increased by the use of the bellows. An 

 isolated platinum, gold, or silver wire was introduced from above, 

 penetrating to the required depth into the saline mass. When 

 electrical currents had to be observed, the crucible was brought, 

 by means of its wire support, into connexion with one end-wire 

 of a multiplier, the platinum wire in the salt being in connexion 

 with the other wire of the multiplier. When, on the other hand, 



* Tranolatcd by Dr. F. Guthrie from PoggcndorflT s Annalcn for April 1858. 



